Spatio‐temporal dynamics of water quality and eutrophication in Lake Taihu, China

Abstract

Water quality evaluation in Lake Taihu, China, is vital for the regional water security. Recent studies have focused on understanding the spatio‐temporal dynamics of water conditions using long‐term data series. In this study, water conditions of Lake Taihu during non‐cyanobacterial/cyanobacterial growth periods were assessed based on water quality index (WQI), trophic level index (TLI), chlorophyll a concentration, and algal density; the spatio‐temporal changes in water quality were quantified, and their corresponding driving forces were discussed. The study employed water quality data from 2013 to 2018 and algal density data from 2013 to 2017. The results revealed that the water conditions varied over the years; it was the poorest in 2013, improved slightly in 2014, deteriorated during 2015–2017, and improved again in 2018. Slow algal growth was observed from May to July, which accelerated from August–September. The TLI in Lake Taihu may increase due to significant inflow during wet years, which may increase the eutrophication area and algae density in the following year, necessitating extreme caution. The northwestern part of Lake Taihu exhibited a lower WQI and higher TLI than its southeastern part. In the bays with high TLI, the WQI during the cyanobacterial growth period was lower than the non‐cyanobacterial growth period; the converse was observed in bays with low TLI. The results of this study imply that water conditions of Lake Taihu could be enhanced by reducing the nutrient load in wet seasons and wet years and improving the hydrodynamic conditions through water diversion, especially in Zhushan and Meiliang bays.

An evaluation of seasonal and spatial variation of water quality parameters of the Mamloo Reservoir in Iran by multivariable analysis

“…The region in the surroundings of the MDR and to its upstream is enriched with organic matter and phosphorous. But due to the mountainous terrain, a comparable amount of agricultural drainage is not distinguished in the region (Li et al, 2021b;Steinsberger et al, 2020). In addition to which several industrial and residential units are present in the Jajrood Watershed Basin, which is a crucial factor, in respect to the entrance of nutrients into the reservoir; besides which, the presence of a stable thermal strati cation in the several months, imposes its own exclusive modi cations, in the context with water quality, as to the reservoir.…”

“…These ecosystems are nevertheless, susceptible to water pollution in the way of eutrophication, which can be stated to be, one of the most insistent environmental problems, in relevance with the management of water resources, across the globe (Farral et al ., 2018;Guan, 2020). Eutrophication, which is primarily attributed to the incessant increment in the input of required nutrients into the aquasystems, alike nitrogen and phosphorous, results in negative and destructive impacts on ecological functions presented by water resources (Mendoza et al, 2015;Cai et al, 2020;Li et al 2021b). Even though, the eutrophication process is a long-drawn and a natural one, it is prone to be distinctly enhanced by human activities, thus, creating latent risks, related to matters, such as, ecological development and human wellbeing or health (Ferral et al, 2018; Le Moal et al, 2019;Lin et al 2021).…”

Effect of Grass Buffer Strips on Nitrogen and Phosphorus Removal from Paddy Runoff and Its Optimum Widths

“…Taihu Lake is the third-largest freshwater lake in China. The water environment of Taihu Lake began to deteriorate in the 1990s, with the water quality decreasing from Class I and II to Class V based on the Environmental quality standards for surface water in China [7,8]. The main pollution factors were TN and TP [8][9][10].…”

“…The water environment of Taihu Lake began to deteriorate in the 1990s, with the water quality decreasing from Class I and II to Class V based on the Environmental quality standards for surface water in China [7,8]. The main pollution factors were TN and TP [8][9][10]. Although the treatment of Taihu Lake has achieved some success in recent years, the problem of water eutrophication is still severe [7,10].…”

Environmentally driven risk assessment for algal bloom occurrence in shallow lakes

“…Algal blooms can occur and subside over rather short time scales, which are hence notoriously difficult to observe and predict (Janssen et al 2019, Li et al 2021b, Pyo et al 2022. To effectively and proactively reduce hazards caused by algal blooms in freshwater lakes, numerous algal bloom modelling studies have been conducted.…”